Author: Robert Hyatt
Date: 07:59:33 07/28/01
Go up one level in this thread
On July 28, 2001 at 04:17:18, Uri Blass wrote: >On July 28, 2001 at 01:12:41, Terry McCracken wrote: > >>On July 27, 2001 at 18:58:30, Dann Corbit wrote: >> >>>On July 27, 2001 at 18:44:45, Roy Eassa wrote: >>> >>>>On July 27, 2001 at 16:55:55, Dann Corbit wrote: >>>> >>>>>On July 27, 2001 at 16:51:08, Roy Eassa wrote: >>>>> >>>>>>Be careful, Dann. Dr. Hyatt has argued strongly that ponder should always be >>>>>>on, even with a single CPU. (It seemed counter-intuitive to me too, but you >>>>>>should check out his recent postings -- over the past couple days, I think.) >>>>> >>>>>Not when both engines play on the same machine. >> >> >>>>>No way. >>>> >>>> >>>>Yes way! I reacted the same way (in my head), but I respect Dr. Hyatt and his >>>>arguments are worth reading at least! >>> >>>If you run two engines which are both pondering on a single CPU machine, then >>>you are simply out of your mind. >>> >>>I think you must have misread the arguments. >> >>No Dan he's read the arguements correctly! >> >>Posted by Robert Hyatt (Profile) on July 27, 2001 at 13:28:16: >> >>In Reply to: Re: Permanent Brain ON vs Permanent Brain OFF posted by Uri Blass >>on July 27, 2001 at 11:58:57: >> >> >>On July 27, 2001 at 11:58:57, Uri Blass wrote: >> >>>On July 27, 2001 at 11:18:08, Miguel A. Ballicora wrote: >>> >>>>On July 26, 2001 at 14:41:54, Robert Hyatt wrote: >>>> >>>>>On July 26, 2001 at 12:55:06, Miguel A. Ballicora wrote: >>>>> >>>>>>On July 26, 2001 at 10:43:45, Robert Hyatt wrote: >>>>>> >>>>>>>On July 26, 2001 at 09:56:24, Matthias Gemuh wrote: >>>>>>> >>>>>>>> >>>>>>>>Hi Robert, >>>>>>>> >>>>>>>>I think you just wanted to make a joke. We all know that PONDER OFF hurts nobody >>>>>>>>(Fritz used its full time). PONDER ON on one CPU is very appropriate to arrive >>>>>>>>at wrong engine comparasons. >>>>>>>> >>>>>>>>Regards, >>>>>>>>Matthias. >>>>>>> >>>>>>> >>>>>>>>>>>>both will get 1/2 of the machine and the time controls won't be screwed up. >>>>>>> >>>>>>>ponder=off exposes the opportunity for a program to get into time trouble >>>>>>>because it assumes it will save time with ponder=on when it really can't since >>>>>>>it is disabled... >>>>>> >>>>>>Why the program should assume that it will save time in with ponder=on when >>>>>>it knows that it is off already? >>>>>>Shouldn't a program take this into account? >>>>>>If ponder=off is an option for the program, it should notice the difference >>>>>>and act accordingly IMHO. >>>>>> >>>>>>Regards, >>>>> >>>>> >>>>>because in my case, 99.9% of all games played have ponder=on. I only disable >>>>>pondering to debug so that I can reproduce the same searches over and over >>>>>when necessary. Since almost all real games are played with ponder=on, I don't >>>>>have a special time-allocation formula for ponder=on and another one for >>>>>ponder=off. I just have one that _assumes_ ponder=on. >>>>> >>>>>I see no reason to waste what little time I have working on something that is >>>>>hardly going to be used... >>>> >>>>Well, it is used a lot actually by lots of people already. Most of the people >>>>are running matches with ponder=off for some reasons. >>>>If both engines were tuned for ponder=off, it will be the best condition to >>>>optimze the resources since time used pondering is never as good a time used >>>>thinking. For instance, you have a competitive mindset in your answer but if my >>>>purpose is to run a match between engines to learn a particulat opening, I want >>>>my resources to be used as efficient as possible. That is ponder=off for both. >>>>Maybe you could consider making Crafty to be able to process "ponder=off" >>>>accordingly because there will be users that would benefit from it. >>>> >>>>Regards, >>>>Miguel >>> >>>Crafty is not a commercial program so I guess that the way that users use it is >>>not important for Bob. >>> >>>I also do not think that the difference between ponder on and ponder off is more >>>than 20 elo in most of the practical cases. >>> >>>Uri >> >> >>I disagree. When this first cropped up a couple of years ago, I ran a test, >>gnuchess on a single-cpu, vs crafty on a quad pentium-pro 200, but using only >>one cpu. The quad was far slower than the 500mhz single cpu by a significant >>amount. The match was pretty even (ponder=on) even though crafty had a much >>slower processor. With ponder=off, the match was way more lop-sided in favor >>of GNU because crafty would get into time trouble and near the end of the >>time period it would have to move too quickly to avoid losing on time. >> >>It was _clearly_ worse. And by more like 100 points, too. I adjusted it a bit >>to help, but I have _never_ invested as much time in the ponder=off timing as >>I have in the ponder=on timing. And I never will, any more than I am going to >>try to tune my son's mustang to run on a road coarse when we only take it to >>the 1/8th and 1/4th mile drag strips... >> >>I think you should spend the time making it optimal in the way it will normally >>be used, not in oddball configurations... >> >> >>I ran a bunch of games, everything equal but the hardwar >> >> >>Quote/Hyatt; Nope... no joke at all. Two programs, one machine, my preference >>is ponder=on. > >Note that it is hyatt's opinion. >I said that in most of the practical cases the difference between ponder on and >ponder off is not more than 20 elo. > >The practical cases are usually with the commercial programs. >I am not talking about amatuers like GNUchess. > >I agree that there may be a big difference with amatuers. >One reason is simply the fact that part of the amatuers do not know to ponder so >ponder off is clearly better for them than ponder on. > >I do not know if this was the reason for GNU chess but when I read 100 elo >difference I suspect that this is the reason. > >I do not believe that program are handicapped by more than 100 elo if they do >not know to ponder. > >I believe that the difference is even less than 70 elo(70 elo is the difference >from doubling the speed of the program and it is better to be twice faster and >play without pondering). > >Uri No... the problem was definitely in crafty. I was playing games of 15 minutes for 40 moves. At move 35-40, crafty was in time trouble and made bad moves in many (but not all) games because it had far less time than GNU did. You can't afford to do a 6-8 ply search and move when your opponent is doing 10-12 plies on that same move because he has used his time more reasonably. I fixed the problem in a simplistic way by simply spreading out the time over the time-control-moves in a more uniform way. Very unlike the way a human plays chess of course, but it was one quick-and-dirty way to avoid getting blasted near the end of the time control.
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